I'm running the most current version of SD and OS X 10.5.8, and I'm attempting to do a first time backup in conjunction with Time Machine. Currently my backup is going on 23 hours and it's only about 1/3 of the way done.......

Why is it taking so long and does it normally take this long the first time? This is taking for freaking ever and at it's current pace the backup will be complete friday night if I'm lucky.

The external hard drive I was using for Time Machine. It was going on 41 hours and was only half way done, and to be honest I can't wait a week for this app to do a backup of my hard drive to the edd I'm using for Time Machine.... so I've stopped it.

I'm duplicating a 1 TB Time Machine HD containing 590 GB to a brand new 2 TB HD. Both drives are 7200 RPM and on separate (left & right) USB 2 ports of my MBP, nothing else is connected to either USB hub.

I aborted the first attempt ("Backup - all files") after 4 hours because it was averaging about 3 MB/s, with an estimated completion in the 40 hour range. Purchased a license in hopes that SD would offer some faster options, but my second attempt ("Backup - all files" with Smart Update) is equally glacial.

Prior to starting the clone I drag-and-dropped several test folders containing big and little files and saw typical speeds in the 20 MB/s range, so I know it's not a drive or USB problem.

I'm running nightly TM backups - source and destination are 1TB sata drives and the TM store is currently around 650GB.

The FIRST copy will take a VERY LONG time. Subsequent smart backups completed in about 4-5 hours under Leopard, and now run 6-7 hours under Snow Leopard.

As Dave said, TM is a complex structure and I'll add that while a standard Mac OS drive may contain 100,000 plus files, a well established TM drive will be referencing many million files. Super Duper will copy it - and I believe it is the only safe TM copy mechanism.